MIAMI (NewsNation) — The rise in sightings of a rare, endangered fish is amplifying wildlife officials’ concerns regarding an ongoing outbreak of abnormal fish behavior and dead and dying fish washing ashore in the Florida Keys.

According to the Florida Wildlife Commission (FWC), there have been more than 50 sightings of sick or dead sawfish in the Lower Keys since November. Despite ongoing efforts, the FWC has yet to determine the cause but is actively testing the animals and collecting samples.

Dr. Dean Grubbs, associate director of the Research Coastal and Marine Laboratory at Florida State University, said witnessing the sawfish in distress or dead is “disheartening.”

“It’s heart-wrenching in certain ways because we get distressed if we see one animal that is killed by a person or something,” said Grubbs, who’s dedicated over 15 years to studying smalltooth sawfish.

Residents along the Florida Keys may never encounter a sawfish in their lifetime. So, the initial excitement is understandable, but as the situation unfolds, people are left shocked and in disbelief by what’s happening in the water.

“It was almost like seeing a unicorn or a sasquatch in real life,” Craig Scherzer said while vacationing in the Florida Keys. “It’s something to see them. It’s like wow, they do exist, but then it’s sad because they’re dying, too.”

Sawfish are a critically endangered species and are rarely seen, if at all, in the Florida Keys. That’s why the last three months have been puzzling for researchers working to solve the alarming issue of sawfish washing ashore.

“I am waiting as much as everyone else to try and figure out what it is. none of that is normal. They should not be swimming in a circle. They should not be swimming in water so shallow their maelstrom is out of the water. All of that is abnormal behavior,” Grubbs said.